DIAMOND REO CAMPAIGN NO 103.MANFD 1-1 1971 THRU 3-13 1972.TRACTOR.POSSIBILITY THAT AIR DRYER WAS PIPED INCORRECTLY FROM AIR DRYER TO AIRGOVERNOR.(CORRECT BY INSPECTING AND INSTALLING LINE FROM AIR GOVERNOR TO AIRTANK, WITH CHECK VALVE IN LINE FROM AIR FILTER TO AIR TANK.)